1. Field of the Invention
The present invention relates to a support film for tape, and particularly a support film for tape having barrier properties, and a tape using the same.
Priority is claimed on Japanese Patent Application No. 2010-171208, filed Jul. 29, 2010, the content of which is incorporated herein by reference.
2. Description of Related Art
A tape on which an adhesive layer is formed on one surface of a sheet-shaped or film-shaped support has been widely used for various purposes such as for medical use or industrial use. In addition to adhesive materials, in some cases a plasticizer and the like are combined to the adhesive layer of the tape. Since there is a concern over a negative effect due to adsorption of the plasticizer depending on materials of a support, it is preferable that at least a surface of the support which comes into contact with the adhesive layer has barrier properties.
A gas barrier film disclosed in Patent Document 1 (Japanese Unexamined Patent Application, First Publication No. 2003-136645) has been used as a film material having barrier properties. In this gas barrier film, a barrier coating film is formed by applying a barrier coating material which is obtained by mixing montmorillonite, which is a layered inorganic compound, and a water-soluble polymer compound on one surface of a plastic base film.
In addition, Patent Document 2 (Japanese Unexamined Patent Application, First Publication No. H08-127531) discloses a film-shaped support for percutaneously administered medicine including a barrier film formed of polyethylene terephthalate (PET) and the like. Patent Document 3 (Japanese Unexamined Patent Application, First Publication No. 2009-249298) discloses a film-shaped support for a patch having barrier properties by providing a vapor-deposited layer formed of aluminum and the like. Patent Document 4 (Japanese Unexamined Patent Application, First Publication No. 2009-173626) discloses a support for a patch which is obtained by laminating an elastic base film layer and a polyester resin film layer which includes a groove, the width of which changes according to elongation of the base film.
On the other hand, since the tape is attached to an object in a state with increased length and area than an initial state due to elongation, in many cases, it is preferable that the support used for the tape have excellent flexibility.
A gas barrier film disclosed in Patent Document 1 is conceived to be used mainly for packaging materials of food products, electronic components, and the like, and as materials of a base film, a biaxially-drawn polyester film, a polypropylene film and the like are disclosed; however, since it is not certain that these materials have high flexibility, the films may not reliably have a preferable configuration as they are, as a support film for tape which is sometimes elongated when attached.
Herein, the inventors found the following problems when configuring a support film for tape by performing selection and application of a material with further excellent flexibility as a support.
That is, it is possible to prepare a support film for tape using a support formed of a material with excellent flexibility; however, if the support film for tape is elongated in order to be attached to an object or after being attached thereto, a barrier layer cannot sufficiently respond to shape change of the support due to the elongation, and cracks or the like are generated on the barrier layer, in some cases.
If cracks or the like are generated on the barrier layer, barrier properties of the barrier layer are degraded, and if the cracks or the like pass through in a thickness direction of the barrier layer, the barrier properties are lost. As a result, there is a problem with a case in which the barrier layer does not realize an expected performance in use and the negative effect to the support due to the plasticizer described above cannot be sufficiently suppressed.
On the other hand, as disclosed in Patent Document 2, in a configuration including a barrier film formed of PET and the like, there is a problem in that flexibility of the support is not sufficiently realized due to PET and the like, which have low flexibility.